GOODWILL AND OTHER INTANGIBLE ASSETS GOODWILL AND OTHER INTANGIBLE ASSETS--Schedule of Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Goodwill [Roll Forward]
Balance at beginning of period	$ 204,084	$ 204,084	$ 204,084
Goodwill	676,949	$ 0	0
Balance at end of period	$ 881,033		$ 204,084